Ventilated pulley



Oct. 13, 1936. A. KIMBLE VENTILATED PULLEY Filed March 23, 1936 Inventor 6 A usi'z'n Kim b 16 Patented Oct. 13, 1936 VENTILATED PULLEY Austin Kimble, Canoga Park, Calif., assignor to Original A. Kimble, Inc., Canoga Park, Calif., a corporation of California Application March 23, 1936, Serial No. 70,342

6 Claims. (01. 74230.7)

This invention relates a ventilated pulleys and particularly to such devices employed for variable speed power transmission by means of belts. The main objects 'of this invention are to provide an improved ventilated pulley of simplified and'less costly construction; to provide a ventilated pulley construction having an improved arrangementwh'ereby an increased flow of air over the pulley surface is aiforded; to provide an improved ventilated pulley wherein a large volume of air is drawn across both belt surfaces asthe belt passes over the pulley; and to provide an improved ventilated pulley construction by A which 'air is admitted at oneedge of the belt and drawn across the belt surfaces to the opposite edge.

'A specific embodiment of this invention is shown in the accompanying drawing, wherein: Fig. 1 is a perspective View of a pulley illustrating the improved arrangement.

' Fig. 2 is a sectional view of the same, and

Fig. 3 is an end view ofthe same.

As shown in the drawing the improved pulley comprises a cylindrical body or hub I, having an enlarged flange 2 on one end, and a smaller notched or grooved flange 3 on its opposite end. Also the pulley is provided with a relatively large counterbore l extending into the body of the pulley for substantially one-half its width from the end of the pulley on which the small notched flange 3 is disposed.

The large flange 2 is constructed in the form of a centrifugal air impeller or blower, and is provided with a plurality of angularly spaced radial ribs or blades 5 on its inner surface and an annular ring-shaped end plate 6 suitably secured to the side edges of the blades 5. The end plate or ring 6 as shown, is made to have a width of substantially one-half the width of the flange 2 so as to leave an intake opening 1 between the inner margin of the ring 6 and the body of the pulley I; and a belt retaining shoul der 2.l is provided at the base of the blades to prevent contact between the belt and the blade edges. As shown the end ring 6 of the blower wheel is secured to the blades or ribs 5 by means of bolts or screws 8. However, it will be understood that any other suitable means of fastening may be employed.

Thus the structure is such that the pulley I comprises an outwardly projecting hub for a multi-blade centrifugal blower wheel, which in accordance with well-known centrifugal principles will, in operation, draw large quantities of air into its central opening I, and discharge the same from its outer periphery.

In order to provide for cooling the body of the pulley l or dissipating any heat of friction that might be generated therein, a plurality of passages 9 are provided leading from the inner end of the counterbore 4 to the surface of the hub of the blower wheel at points between the blades 5 thereof, and within the confines of the blade edges. Thus in operation a constant flow of air passes through the passages 9 into the blower wheel and is discharged from its periphery,

As shown the small flange 3 is of the usual width of such flanges for retaining the belt on the pulley. However, in the present invention, this flange is characterized by a plurality of radial notches or cutout portions l0 which extend from the periphery of the flange 3 substantially to the face of the pulley l, the notches H) as shown being so spaced and proportioned that their width will be substantially equal to the remaining flange portion between the several notches. The purpose of these notches, or, grooves 10 is'to admit air at the'outer edge of the belt, shown at H2 in Fig. 2, which air will tend to' travel across both the outer and inner surfaces of the belt toward the blower wheel at the opposite end of the pulley, and in operation the course of the air will be substantially that indicated by the arrows II in Fig. 2. It will be understood, however, that the spacing and proportioning of the notches Ill may be varied to suit the pulley size and the work for which it is designed.

In operation the herein described pulley will ordinarily be employed as the driving element of the power transmission, and a variable speed will be obtained by permitting a predetermined slip between the driven belt and the pulley. This slip and the attending friction between the belt and the pulley will cause the production of considerable frictional heat not only in the body of the pulley, but also in the belt. This heat, however, will be dissipated by means of the air currents passing over the belt through the action of the blower wheel, comprising the enlarged flange 2. As the pulley is rotated air will be drawn into the opening 1 at the inner margin of the ring 6 through centrifugal action, which will cause the air to be discharged from the periphery of the blower wheel.

Because of the multi-blade construction air in large volumes will be drawn into the blower and this air will approach the blower from a generally axial direction, coming mainly from the end of the pulley on which the small flange 3 is disposed.

Thus the air drawn into the pulley will be drawn across the entire surface of the belt passing over the pulley. Because of the notches I in the small flange 3 this air will be admitted at the outer edge of the belt and pass under the belt, particularly as it leaves frictional engagement with the pulley, as well as over the same, assuring a maximum efficiency in dissipation of the heat generated in the belt.

The main advantages of the herein described invention lie in the arrangement wherein air is drawn across the surface of the pulley in a generally axial direction, rather than from the sides of the pulley, this effect being produced by the use of the end ring 6 mounted on the outer edges of the blower blades and in the notched construction of the small flange 3 on the outer end of the pulley by which air is admitted to the surface of the belt at its outer edge, such air being drawn across both the outer and inner surfaces of the belt wherever possible.

Also it has been found in practice that the herein described ventilated pulley construction provides a much greater air flow and a more efficient air distribution across the surface of the belt than is had in ventilated pulleys heretofore used, thus greatly increasing the life and efficiency of the driven belt.

Although but one specific embodiment of this invention is herein shown and described, it will be understood that certain details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined in the following claims.

I claim:

1. A ventilated pulley comprising a pulley body having a relatively wide radial flange at one end, a plurality of angularly spaced radial blades on the inner face of said flange, and an annular ring secured to the inner edges of said blades, the inner margin of said ring being spaced from the surface of said pulley body.

2. A ventilated pulley comprising a pulley body having a relatively wide radial flange at one end,

a plurality of angularly spaced radial blades on the inner face of said flange extending from said pulley body to the periphery of said flange, and an annular ring secured to the inner edges of said blades, the outer margin of said ring being flush with the ends of said blades, and the inner margin of said ring being spaced from the surface of said pulley body.

3. A device of the class described comprising a pulley having a belt retaining flange at one end, and a centrifugal blower wheel at the opposite end having an air intake opening facing and adjacent the belt surface of said pulley, said belt retaining flange having a plurality of angularly spaced openings therethrough.

4. A device of the class described comprising a pulley having a belt retaining flange at one end, and a centrifugal blower wheel at the opposite end having an air intake opening facing and adjacent the belt surface of said pulley, said belt retaining flange having a plurality of angularly spaced peripheral notches extending substantially to the belt surface of said pulley.

5. A device of the class described comprising a pulley having a belt retaining flange at one end, and a centrifugal blower wheel at the opposite end having an air intake opening facing and adjacent the belt surface of said pulley, said belt retaining flange comprising a plurality of angularly spaced flange segments projecting from the periphery of said pulley.

6. A device of the class described comprising a pulley having a belt retaining flange at one end, and a centrifugal blower wheel at the opposite end having an air intake opening facing and adjacent the belt surface of said pulley, said pulley having a relatively large counterbore in said one end and a plurality of air passages leading from said counterbore into said blower, and said belt retaining flange having a plurality of angularly spaced openings therethrough adjacent the belt surface of said pulley.

AUSTIN KIMBLE. 

